Efficient method for enantioselective synthesis of dexmethylphenidate hydrochloride (focalin®)

An improved economical and eco friendly process for the enantioselective resolution of methylphenidate free base to give (2R,2’R)-(+)-threomethylphenidate via diastereomeric salt preparation with (+)-di-para-toluyl-D-tartaric acid has been achieved. The racemic resolution performed under mild and neutral conditions having simple unit operation making process feasible for large scale production of dexmethylphenidate hydrochloride.